Core taking apparatus



F. THRIFT CORE TAKING APPARATUS July 4, 1939.

Filed April 15, 19:54

III I Patented July 1939 burr so STATES PATENT OFFICE 90laims.

This invention relates .to a core taking apparatus.

An object of the invention is to provide apparatus of the character described for taking 6 cores or samples of the iormation encountered during well drilling operations and embodies a core barrel with novel means whereby the same may be landed in position in, and maintainedin position in, the drilling apparatus by the pres- 10 sure of the drilling fluid...

Another object is to provide the combination with drilling apparatus oi a core barrel arranged to be held in position therein, in readiness to take a core or sample, by the pressure of the drilling is fluid and having means for closing'the channel, through which the drilling fluid as delivered to the drill, in case the barrel is displaced from core receiving position to indicate to the operator that the barrel has been so displaced.

A further object is to provide in a. device of the character described, a novel construction whereby the drilling fluid may be utilized to force the core barrel into its final position in the drill stem and whereby the pressure of the drilling fluid will be released when the core barrel has landed in home position to indicate to the operator that the core barrel is in home position to take a core or sample. a

The invention disclosed herein comprises cer- 30 tain improvements in construction and method of operation over my Patent No. 1,999,428, Core taking apparatus granted April 30, 1935.

With the above and other objects in view the invention has particular relation to certain novel features of construction, operation and arrangement of parts, an example of which is given in this specification and illustrated in the accompanying drawing, wherein:

Figure 1 shows aside view of the core tak- 40 ing apparatus shown partly in section.

Figure 2 shows a vertical sectional view of the intermediate portion thereof, and

Figure 3 shows a vertical sectional view 01' the drill as attached to the lower end of the drill 45 stem, showing the lower end of the core barrel in home position.

7 Referring now more particularly to the drawing wherein like numerals of reference designate similar parts in each of the figures, the numeral 50 I designates a tubular drill stem whose .sections are connected by suitable tool Joints as 2 and attached to the lower end of the drill stem there is a drill 3 of any conventional construction, and

. having an axial bore 4 through the lower end 55 thereof, for theinlet or the sample. Above its lower end the bore 4 is reduced in diameter forming the seat 5 to receive and support the lower end of the tubular core barrel 6. -The lower end oi this core barrel has sample retaining means of any conventional construction. As shown the 5 core retaining means comprise flexible fingers 1 whose lower ends are secured in the core barrel and whose upper ends are inwardly curved and free.

There is a stem ll whose lower end is enlarged forming the plunger 9 and the lower end of this plunger is connected to the upper end of said barrel preferably by threads. This plunger and the upper end of the barrel fits closely within the cylinder in whose upper end is screwed into the tool joint above. Beneath the upper end or the core barrel said barrel is provided with lateral openings It and within the barrel beneath said openings there is the valve seat i pinned in place by the pin it, or otherwise se- 2Q} cured therein. The seat is normally closed by means of the upwardly opening wall valve it.

The cylinder I0 is provided with the outlet ports l5 which are cleared by the.plunger 9 when the core barrel reaches its home position.

The upper end of the rod 9 is formed with a conical shaped head H for a purpose to be hereinafter stated and the lower end of the drill may be formed with a pilot core bit l6 of any selected design.

In carrying on drilling operations when it is desiredto take a core, the core taking appara' tus may be assembled as shown and a suitable grapple attached to the head I1 and the appatus let down through the drill stem by means of a cable attached to the grapple; or the core barrel may be dropped through the stem without the use of a cable.

The lower end of the core barrel 6 will enter the enlarged upper end of the bore 4, and the. 40 plunger 9 will enter the tool joint above and the drilling fluid above, under pump pressure, will force said plunger 9 downwardly through the cylinder l0 until said plunger clears the ports l5 at which time the lower end of the core barrel 5 will land on the seat 5, thereupon the pressure being released the pump will be speeded up indicating that the barrel has landed in some position.

The grapple may then be detached from the head I'I, if a cable has been used to lower the barrel, and the cable removed and drilling may then be proceeded with. A core or sample of the formation will enter the bore 4 and pass up into the core barrel above. Any liquid that may 66 be in said core barrel will pass out through the seat ii, the valve I4 lifting for that purpose, and said liquid will pass on out through the openings ll. While the core is being taken drilling fluid will be forced under pressure down through the drill stem and will pass out through the channels i8, it which lead from said drill stem and diverge through the drill 3 whereby drilling fluid is discharged in front of the respective cutter blades or other cutters is.

The pressure of the drilling fluid against the plunger 9 will ordinarily maintain the barrel in home position in readiness to receive the sample; but if the core should engage beneath the barrel or for any reason the barrel should be lifted ofl its seat so that a core or-other sample does not enter the barrel the plunger 9 will move upwardly with the barrel and close the ports I! to the end that the pump is stalled or the pressure increased to indicate to the operator that a core is not being taken.

Sometimes the core which enters the barrel will expand or lengthen sufliciently to lift the barrel and'close the ports l5, thereby blocking the fluid passage and causing an increase of pressure to indicate to the operator thatthe barrel has been displaced from its home position.

As will be understood, therefore, I utilize the increase in back pressure on the drilling fluid to indicate either a filling or obstructing of the core barrel, and preferably effect this increase by lifting or elevating the barrel by means of upward pressure thereon created by filling or clogging, the lifting movement serving to obstruct the flow and increase the back pressure. By the expression fllling of the barrel, as used in the claims, is meant either a complete filling of the barrel or any obstruction which causes an increase in pressure.

when a core or sample has been taken the cable and grapple may be lowered and the grapple engaged over the head i1, and the core barrel with the sample therein may then be removed in an obvious manner.

What I claim is:

1. A core taking apparatus comprising a tubular stem having a drill attached to the lower end thereof and provided with a sample receiving inlet, said stem forming a conduit through which fluid under pressure may be supplied to the drill, a cylinder in the stem having an outlet port through which said fluid may pass, a barrel movable downwardly into andupwardly out 01' the stem, the upper end of the barrel forming a plunger arranged to enter the cylinder as the barrel moves downwardly whereby the pressure of the fluid in the stem above may act to force the plunger downwardly to clear said port and to move the barrel downwardly to seat its lower end on the drill in alignment with the inlet, said barrel being unanchored to the stem to permit upward pressure against the barrel to move the barrel upwardly relative to the stem to cause the plunger to block said port to eflect an increase of pressure of the pressure fluid.

2. A core taking apparatus including a tubular drill having a fluid conduit, a core barrel adapted to be supported in said drill and retained therein by hydraulic pressure, means for introducing fluid under pressure to said conduit, and means actuated by upward pressure on the core barrel for interrupting the flow of fluid through the conduit and increasing the pressure of the fluid above the core barrel to indicate that the core barrel has been raised 01! of its seat, said last mentioned means including a cylinder carried by said drill and having a port through which the fluid may pass, and a plunger non-movably carried by the upper end of barrel and normally clear of said port when the barrel is seated in the drill but movable to a position to close the port when the core barrel is elevated.

33. A core taking apparatus including a tubular drill having a sample receiving inlet and a seat located above said inlet,- a core barrel adapted to be supported in said drill on said seat and retained thereon by hydraulic pressure, means for introducing fluid under pressure to said drill, means actuated by upward pressure on the core barrel for interrupting the flow of fluid and increasing the back pressure thereof to indicate that the core barrel has been raised oil its seat, and a check valve mounted in the upper portion 01 said core barrel and normally positioned below said last mentioned means when the core barrel is seated in the drill stem, said valve being normally held on its seat by .the pressure of the fluid but being adapted to be relieved from said pressure when said last mentioned means interrupts the flow of fluid through the conduit.

4. Acore taking apparatus including a tubular drill stem having a fluid conduit, a core barrel adapted to be supported in said drill stem and retained therein by hydraulic pressure, means for introducing fluid under pressure to said conduit, means actuated by upward pressure on the core barrel for interrupting the flow of fluid through the conduit and increasing the pressure of the fluid above the core barrel to indicate that the core barrel has been raised off its seat, said lastmentioned means including a plunger carried by said core barrel and movable to a position to close said conduit when the core barrel .is raised, saidcore barrel being provided with a valve seat positioned below said plunger and a port positioned between the valve seat and plunger and placing the interior of the barrel in communication with the interior of the drill stem, and a valve associated with said seat and normally maintained on said seat by the pressure of the fluid passing through said conduit, said valve being relieved from pressure of the fluid when the plunger closes said conduit.

5. A core taking apparatus including a tubular drill stem having a fluid conduit, a core barrel adapted to be suppoted in' said drill stem and retained therein by hydraulic pressure, means for introducing fluid under pressure to said conduit, means actuated by upward pressure on the core barrel for interrupting the flow of fluid through the conduit and increasing the pressure of the fluid above the core barrel to indicate that the core barrel has been raised oil. its seat, said lastmentioned means including a cylinder carried by said'stem and having a port through which the fluid may pass, and a plunger carried by the barrel and normally clear of said port when the barrel is seated in the drill stem but movable to a position to close the port when the barrel is elevated, said core barrel being provided with a valve seat positioned below said plunger and a port positioned between the valve seat and plunger and placing the interior of the barrelin communication with the interior of the drill stem, and a valve associated with said seat and normally maintained on said seat by the pressure of the fluid passing through said conduit. said second-mentioned port being so arranged with respect to the flrst port when the core barrel is seated, that closing of the flrst port by the plunger will not "close the second port whereby barrel moves downwardly whereby the pressure .of the fluid in the stem above may act to force the plunger downwardly to clear said port and to move the barrel downwardly to seat'its lower end on the drill in alignment with the inlet, said barrel being unanchored to the stem to permit upward pressure against the barrel to move the barrel upwardly relative to the stem to cause the plunger to block said port to eflectan increase of pressure 01' the pressure fluid, said barrel being provided with a valve seat below said plunger and a port above said seat to place the interior of the barrel in communication with the interior of the stm,'and a valve associated with said seat and normally maintained thereon by the pressure of thefluid passing through the conduit, said,

valve being relieved from pressure of the fluid when the plunger blocks said first .mentioned Port. i.

7. A core taking apparatus including a tubular drill stem having a fluid conduit, a core barrel adapted to be positioned in said drill stem and retained in operativetposition byhydfiaulic pres-' sure, means for introducing fluid under pressure through said conduit, means actuated by upward pressure on the core barrelior interrupting the 5 flow of fluid through the conduit and increasing the pressure of the fluid above the core barrel to indicate that the core barrel has been raised from operative position, and a valve mounted in .the upper portion oi said core barrel and normally positioned below said last mentioned means'when the core barrel is in operative position in the drill stem, said valve being normally held on its seat by the pressure of the fluid but being adapted to be relieved from said pressure when said last mentioned means interrupts the flow of fluid through the conduit.

.8. A core taking apparatus including a tubular drill stem having a fluid conduit, a core barrel adapted to be supported in said drill stem and retained therein by hydraulic pressure, means for introducing fluid under pressure to said conduit, means actuated by upward movement of the core barrel for interrupting'the flowof fluid through the conduit and increasing the pressure 101' the fluid above the, core barrel to indicate that the core barrel has been raised'in the stem, said last mentioned means including a plunger carried by the core barrel and movable to a position to close said conduit when the core barrel is raised, said core barrel being provided with a port positioned to place the interior of the barrel in com-' munication with the interior of the drill stem and being so arranged with respect to the plunger that the closing of said conduit by the plunger willprevent the entrance of the fluid under said ,increased pressure through the port.

9. A core takingapparatus including a tubular drill stem having a fluid conduit, 8. core barrel adapted to be positioned in said drill stem and retained in operative position by hydraulic pressure, means for introducing fluid under pressure through said conduit, means actuated by upward pressure on the core barrel for interrupting the flow of fluid through the conduit and increasing the pressure of the fluid above the core barrel to indicate that the core barrel has been raised in the stem, said core barrel being provided with a port positioned to place the interior of the barrel in communication, with the interior of the drill stem and being so arranged with respect to said fluid'interrupting means that the interruption to the flow of fluid through'said conduit by said last'mentioned means will prevent the entrance of the fluid under said increased pressure through the port. w 

